diff options
Diffstat (limited to 'sql/handler.h')
| -rw-r--r-- | sql/handler.h | 487 |
1 files changed, 392 insertions, 95 deletions
diff --git a/sql/handler.h b/sql/handler.h index e74a2c6c42c..8464bbb3823 100644 --- a/sql/handler.h +++ b/sql/handler.h @@ -404,6 +404,13 @@ enum row_type { ROW_TYPE_NOT_USED=-1, ROW_TYPE_DEFAULT, ROW_TYPE_FIXED, /** Unused. Reserved for future versions. */ ROW_TYPE_PAGE }; +/* Specifies data storage format for individual columns */ +enum column_format_type { + COLUMN_FORMAT_TYPE_DEFAULT= 0, /* Not specified (use engine default) */ + COLUMN_FORMAT_TYPE_FIXED= 1, /* FIXED format */ + COLUMN_FORMAT_TYPE_DYNAMIC= 2 /* DYNAMIC format */ +}; + enum enum_binlog_func { BFN_RESET_LOGS= 1, BFN_RESET_SLAVE= 2, @@ -1243,6 +1250,7 @@ inline LEX_STRING *hton_name(const handlerton *hton) #define HTON_ALTER_NOT_SUPPORTED (1 << 1) //Engine does not support alter #define HTON_CAN_RECREATE (1 << 2) //Delete all is used for truncate #define HTON_HIDDEN (1 << 3) //Engine does not appear in lists +#define HTON_FLUSH_AFTER_RENAME (1 << 4) #define HTON_NOT_USER_SELECTABLE (1 << 5) #define HTON_TEMPORARY_NOT_SUPPORTED (1 << 6) //Having temporary tables not supported #define HTON_SUPPORT_LOG_TABLES (1 << 7) //Engine supports log tables @@ -1304,6 +1312,22 @@ struct THD_TRANS void reset() { no_2pc= FALSE; modified_non_trans_table= FALSE; } bool is_empty() const { return ha_list == NULL; } THD_TRANS() {} /* Remove gcc warning */ + + unsigned int m_unsafe_rollback_flags; + /* + Define the type of statemens which cannot be rolled back safely. + Each type occupies one bit in m_unsafe_rollback_flags. + */ + static unsigned int const MODIFIED_NON_TRANS_TABLE= 0x01; + static unsigned int const CREATED_TEMP_TABLE= 0x02; + static unsigned int const DROPPED_TEMP_TABLE= 0x04; + + void mark_created_temp_table() + { + DBUG_PRINT("debug", ("mark_created_temp_table")); + m_unsafe_rollback_flags|= CREATED_TEMP_TABLE; + } + }; @@ -1427,7 +1451,6 @@ struct st_table_log_memory_entry; class partition_info; struct st_partition_iter; -#define NOT_A_PARTITION_ID ((uint32)-1) enum ha_choice { HA_CHOICE_UNDEF, HA_CHOICE_NO, HA_CHOICE_YES }; @@ -1438,6 +1461,7 @@ enum enum_stats_auto_recalc { HA_STATS_AUTO_RECALC_DEFAULT= 0, typedef struct st_ha_create_information { CHARSET_INFO *table_charset, *default_table_charset; + LEX_CUSTRING tabledef_version; LEX_STRING connect_string; const char *password, *tablespace; LEX_STRING comment; @@ -1445,7 +1469,7 @@ typedef struct st_ha_create_information const char *alias; ulonglong max_rows,min_rows; ulonglong auto_increment_value; - ulong table_options; + ulong table_options; ///< HA_OPTION_ values ulong avg_row_length; ulong used_fields; ulong key_block_size; @@ -1469,18 +1493,21 @@ typedef struct st_ha_create_information uint merge_insert_method; uint extra_size; /* length of extra data segment */ enum ha_choice transactional; - bool frm_only; ///< 1 if no ha_create_table() bool varchar; ///< 1 if table has a VARCHAR enum ha_storage_media storage_media; ///< DEFAULT, DISK or MEMORY enum ha_choice page_checksum; ///< If we have page_checksums engine_option_value *option_list; ///< list of table create options + /* the following three are only for ALTER TABLE, check_if_incompatible_data() */ ha_table_option_struct *option_struct; ///< structure with parsed table options ha_field_option_struct **fields_option_struct; ///< array of field option structures ha_index_option_struct **indexes_option_struct; ///< array of index option structures + + bool tmp_table() { return options & HA_LEX_CREATE_TMP_TABLE; } } HA_CREATE_INFO; + /** In-place alter handler context. @@ -2182,34 +2209,61 @@ uint calculate_key_len(TABLE *, uint, const uchar *, key_part_map); #define make_prev_keypart_map(N) (((key_part_map)1 << (N)) - 1) -/** - Index creation context. - Created by handler::add_index() and destroyed by handler::final_add_index(). - And finally freed at the end of the statement. - (Sql_alloc does not free in delete). -*/ - -class handler_add_index : public Sql_alloc +/** Base class to be used by handlers different shares */ +class Handler_share { public: - /* Table where the indexes are added */ - TABLE* const table; - /* Indexes being created */ - KEY* const key_info; - /* Size of key_info[] */ - const uint num_of_keys; - handler_add_index(TABLE *table_arg, KEY *key_info_arg, uint num_of_keys_arg) - : table (table_arg), key_info (key_info_arg), num_of_keys (num_of_keys_arg) - {} - virtual ~handler_add_index() {} + Handler_share() {} + virtual ~Handler_share() {} }; -class Query_cache; -struct Query_cache_block_table; + /** The handler class is the interface for dynamically loadable storage engines. Do not add ifdefs and take care when adding or changing virtual functions to avoid vtable confusion + + Functions in this class accept and return table columns data. Two data + representation formats are used: + 1. TableRecordFormat - Used to pass [partial] table records to/from + storage engine + + 2. KeyTupleFormat - used to pass index search tuples (aka "keys") to + storage engine. See opt_range.cc for description of this format. + + TableRecordFormat + ================= + [Warning: this description is work in progress and may be incomplete] + The table record is stored in a fixed-size buffer: + + record: null_bytes, column1_data, column2_data, ... + + The offsets of the parts of the buffer are also fixed: every column has + an offset to its column{i}_data, and if it is nullable it also has its own + bit in null_bytes. + + The record buffer only includes data about columns that are marked in the + relevant column set (table->read_set and/or table->write_set, depending on + the situation). + <not-sure>It could be that it is required that null bits of non-present + columns are set to 1</not-sure> + + VARIOUS EXCEPTIONS AND SPECIAL CASES + + If the table has no nullable columns, then null_bytes is still + present, its length is one byte <not-sure> which must be set to 0xFF + at all times. </not-sure> + + If the table has columns of type BIT, then certain bits from those columns + may be stored in null_bytes as well. Grep around for Field_bit for + details. + + For blob columns (see Field_blob), the record buffer stores length of the + data, following by memory pointer to the blob data. The pointer is owned + by the storage engine and is valid until the next operation. + + If a blob column has NULL value, then its length and blob data pointer + must be set to 0. */ class handler :public Sql_alloc @@ -2262,7 +2316,6 @@ public: uint ref_length; FT_INFO *ft_handler; enum {NONE=0, INDEX, RND} inited; - bool locked; bool implicit_emptied; /* Can be !=0 only if HEAP */ bool mark_trx_done; const COND *pushed_cond; @@ -2323,6 +2376,21 @@ public: virtual void unbind_psi(); virtual void rebind_psi(); +private: + /** + The lock type set by when calling::ha_external_lock(). This is + propagated down to the storage engine. The reason for also storing + it here, is that when doing MRR we need to create/clone a second handler + object. This cloned handler object needs to know about the lock_type used. + */ + int m_lock_type; + /** + Pointer where to store/retrieve the Handler_share pointer. + For non partitioned handlers this is &TABLE_SHARE::ha_share. + */ + Handler_share **ha_share; + +public: handler(handlerton *ht_arg, TABLE_SHARE *share_arg) :table_share(share_arg), table(0), estimation_rows_to_insert(0), ht(ht_arg), @@ -2330,18 +2398,21 @@ public: in_range_check_pushed_down(FALSE), ref_length(sizeof(my_off_t)), ft_handler(0), inited(NONE), - locked(FALSE), implicit_emptied(0), mark_trx_done(FALSE), + implicit_emptied(0), mark_trx_done(FALSE), pushed_cond(0), next_insert_id(0), insert_id_for_cur_row(0), pushed_idx_cond(NULL), pushed_idx_cond_keyno(MAX_KEY), auto_inc_intervals_count(0), - m_psi(NULL) + m_psi(NULL), m_lock_type(F_UNLCK), ha_share(NULL) { + DBUG_PRINT("info", + ("handler created F_UNLCK %d F_RDLCK %d F_WRLCK %d", + F_UNLCK, F_RDLCK, F_WRLCK)); reset_statistics(); } virtual ~handler(void) { - DBUG_ASSERT(locked == FALSE); + DBUG_ASSERT(m_lock_type == F_UNLCK); DBUG_ASSERT(inited == NONE); } virtual handler *clone(const char *name, MEM_ROOT *mem_root); @@ -2456,7 +2527,6 @@ public: int ha_disable_indexes(uint mode); int ha_enable_indexes(uint mode); int ha_discard_or_import_tablespace(my_bool discard); - void ha_prepare_for_alter(); int ha_rename_table(const char *from, const char *to); int ha_delete_table(const char *name); void ha_drop_table(const char *name); @@ -2756,6 +2826,7 @@ private: */ virtual int rnd_pos_by_record(uchar *record) { + DBUG_ASSERT(table_flags() & HA_PRIMARY_KEY_REQUIRED_FOR_POSITION); position(record); return rnd_pos(record, ref); } @@ -2871,10 +2942,15 @@ public: { return FALSE; } virtual char* get_foreign_key_create_info() { return(NULL);} /* gets foreign key create string from InnoDB */ - virtual char* get_tablespace_name(THD *thd, char *name, uint name_len) - { return(NULL);} /* gets tablespace name from handler */ - /** used in ALTER TABLE; 1 if changing storage engine is allowed */ - virtual bool can_switch_engines() { return 1; } + /** + Used in ALTER TABLE to check if changing storage engine is allowed. + + @note Called without holding thr_lock.c lock. + + @retval true Changing storage engine is allowed. + @retval false Changing storage engine not allowed. + */ + virtual bool can_switch_engines() { return true; } virtual int can_continue_handler_scan() { return 0; } /** Get the list of foreign keys in this table. @@ -2936,42 +3012,6 @@ public: virtual ulong index_flags(uint idx, uint part, bool all_parts) const =0; -/** - First phase of in-place add index. - Handlers are supposed to create new indexes here but not make them - visible. - - @param table_arg Table to add index to - @param key_info Information about new indexes - @param num_of_key Number of new indexes - @param add[out] Context of handler specific information needed - for final_add_index(). - - @note This function can be called with less than exclusive metadata - lock depending on which flags are listed in alter_table_flags. -*/ - virtual int add_index(TABLE *table_arg, KEY *key_info, uint num_of_keys, - handler_add_index **add) - { return (HA_ERR_WRONG_COMMAND); } - -/** - Second and last phase of in-place add index. - Commit or rollback pending new indexes. - - @param add Context of handler specific information from add_index(). - @param commit If true, commit. If false, rollback index changes. - - @note This function is called with exclusive metadata lock. -*/ - virtual int final_add_index(handler_add_index *add, bool commit) - { return (HA_ERR_WRONG_COMMAND); } - - virtual int prepare_drop_index(TABLE *table_arg, uint *key_num, - uint num_of_keys) - { return (HA_ERR_WRONG_COMMAND); } - virtual int final_drop_index(TABLE *table_arg) - { return (HA_ERR_WRONG_COMMAND); } - uint max_record_length() const { return MY_MIN(HA_MAX_REC_LENGTH, max_supported_record_length()); } uint max_keys() const @@ -3179,10 +3219,266 @@ public: pushed_idx_cond_keyno= MAX_KEY; in_range_check_pushed_down= false; } + /** + Part of old, deprecated in-place ALTER API. + */ virtual bool check_if_incompatible_data(HA_CREATE_INFO *create_info, uint table_changes) { return COMPATIBLE_DATA_NO; } + /* On-line/in-place ALTER TABLE interface. */ + + /* + Here is an outline of on-line/in-place ALTER TABLE execution through + this interface. + + Phase 1 : Initialization + ======================== + During this phase we determine which algorithm should be used + for execution of ALTER TABLE and what level concurrency it will + require. + + *) This phase starts by opening the table and preparing description + of the new version of the table. + *) Then we check if it is impossible even in theory to carry out + this ALTER TABLE using the in-place algorithm. For example, because + we need to change storage engine or the user has explicitly requested + usage of the "copy" algorithm. + *) If in-place ALTER TABLE is theoretically possible, we continue + by compiling differences between old and new versions of the table + in the form of HA_ALTER_FLAGS bitmap. We also build a few + auxiliary structures describing requested changes and store + all these data in the Alter_inplace_info object. + *) Then the handler::check_if_supported_inplace_alter() method is called + in order to find if the storage engine can carry out changes requested + by this ALTER TABLE using the in-place algorithm. To determine this, + the engine can rely on data in HA_ALTER_FLAGS/Alter_inplace_info + passed to it as well as on its own checks. If the in-place algorithm + can be used for this ALTER TABLE, the level of required concurrency for + its execution is also returned. + If any errors occur during the handler call, ALTER TABLE is aborted + and no further handler functions are called. + *) Locking requirements of the in-place algorithm are compared to any + concurrency requirements specified by user. If there is a conflict + between them, we either switch to the copy algorithm or emit an error. + + Phase 2 : Execution + =================== + + In this phase the operations are executed. + + *) As the first step, we acquire a lock corresponding to the concurrency + level which was returned by handler::check_if_supported_inplace_alter() + and requested by the user. This lock is held for most of the + duration of in-place ALTER (if HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE + or HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE were returned we acquire an + exclusive lock for duration of the next step only). + *) After that we call handler::ha_prepare_inplace_alter_table() to give the + storage engine a chance to update its internal structures with a higher + lock level than the one that will be used for the main step of algorithm. + After that we downgrade the lock if it is necessary. + *) After that, the main step of this phase and algorithm is executed. + We call the handler::ha_inplace_alter_table() method, which carries out the + changes requested by ALTER TABLE but does not makes them visible to other + connections yet. + *) We ensure that no other connection uses the table by upgrading our + lock on it to exclusive. + *) a) If the previous step succeeds, handler::ha_commit_inplace_alter_table() is + called to allow the storage engine to do any final updates to its structures, + to make all earlier changes durable and visible to other connections. + b) If we have failed to upgrade lock or any errors have occured during the + handler functions calls (including commit), we call + handler::ha_commit_inplace_alter_table() + to rollback all changes which were done during previous steps. + + Phase 3 : Final + =============== + + In this phase we: + + *) Update SQL-layer data-dictionary by installing .FRM file for the new version + of the table. + *) Inform the storage engine about this change by calling the + handler::ha_notify_table_changed() method. + *) Destroy the Alter_inplace_info and handler_ctx objects. + + */ + + /** + Check if a storage engine supports a particular alter table in-place + + @param altered_table TABLE object for new version of table. + @param ha_alter_info Structure describing changes to be done + by ALTER TABLE and holding data used + during in-place alter. + + @retval HA_ALTER_ERROR Unexpected error. + @retval HA_ALTER_INPLACE_NOT_SUPPORTED Not supported, must use copy. + @retval HA_ALTER_INPLACE_EXCLUSIVE_LOCK Supported, but requires X lock. + @retval HA_ALTER_INPLACE_SHARED_LOCK_AFTER_PREPARE + Supported, but requires SNW lock + during main phase. Prepare phase + requires X lock. + @retval HA_ALTER_INPLACE_SHARED_LOCK Supported, but requires SNW lock. + @retval HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE + Supported, concurrent reads/writes + allowed. However, prepare phase + requires X lock. + @retval HA_ALTER_INPLACE_NO_LOCK Supported, concurrent + reads/writes allowed. + + @note The default implementation uses the old in-place ALTER API + to determine if the storage engine supports in-place ALTER or not. + + @note Called without holding thr_lock.c lock. + */ + virtual enum_alter_inplace_result + check_if_supported_inplace_alter(TABLE *altered_table, + Alter_inplace_info *ha_alter_info); + + + /** + Public functions wrapping the actual handler call. + @see prepare_inplace_alter_table() + */ + bool ha_prepare_inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info); + + + /** + Public function wrapping the actual handler call. + @see inplace_alter_table() + */ + bool ha_inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info) + { + return inplace_alter_table(altered_table, ha_alter_info); + } + + + /** + Public function wrapping the actual handler call. + Allows us to enforce asserts regardless of handler implementation. + @see commit_inplace_alter_table() + */ + bool ha_commit_inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info, + bool commit); + + + /** + Public function wrapping the actual handler call. + @see notify_table_changed() + */ + void ha_notify_table_changed() + { + notify_table_changed(); + } + + +protected: + /** + Allows the storage engine to update internal structures with concurrent + writes blocked. If check_if_supported_inplace_alter() returns + HA_ALTER_INPLACE_NO_LOCK_AFTER_PREPARE or + HA_ALTER_INPLACE_SHARED_AFTER_PREPARE, this function is called with + exclusive lock otherwise the same level of locking as for + inplace_alter_table() will be used. + + @note Storage engines are responsible for reporting any errors by + calling my_error()/print_error() + + @note If this function reports error, commit_inplace_alter_table() + will be called with commit= false. + + @note For partitioning, failing to prepare one partition, means that + commit_inplace_alter_table() will be called to roll back changes for + all partitions. This means that commit_inplace_alter_table() might be + called without prepare_inplace_alter_table() having been called first + for a given partition. + + @param altered_table TABLE object for new version of table. + @param ha_alter_info Structure describing changes to be done + by ALTER TABLE and holding data used + during in-place alter. + + @retval true Error + @retval false Success + */ + virtual bool prepare_inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info) + { return false; } + + + /** + Alter the table structure in-place with operations specified using HA_ALTER_FLAGS + and Alter_inplace_info. The level of concurrency allowed during this + operation depends on the return value from check_if_supported_inplace_alter(). + + @note Storage engines are responsible for reporting any errors by + calling my_error()/print_error() + + @note If this function reports error, commit_inplace_alter_table() + will be called with commit= false. + + @param altered_table TABLE object for new version of table. + @param ha_alter_info Structure describing changes to be done + by ALTER TABLE and holding data used + during in-place alter. + + @retval true Error + @retval false Success + */ + virtual bool inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info) + { return false; } + + + /** + Commit or rollback the changes made during prepare_inplace_alter_table() + and inplace_alter_table() inside the storage engine. + Note that in case of rollback the allowed level of concurrency during + this operation will be the same as for inplace_alter_table() and thus + might be higher than during prepare_inplace_alter_table(). (For example, + concurrent writes were blocked during prepare, but might not be during + rollback). + + @note Storage engines are responsible for reporting any errors by + calling my_error()/print_error() + + @note If this function with commit= true reports error, it will be called + again with commit= false. + + @note In case of partitioning, this function might be called for rollback + without prepare_inplace_alter_table() having been called first. + @see prepare_inplace_alter_table(). + + @param altered_table TABLE object for new version of table. + @param ha_alter_info Structure describing changes to be done + by ALTER TABLE and holding data used + during in-place alter. + @param commit True => Commit, False => Rollback. + + @retval true Error + @retval false Success + */ + virtual bool commit_inplace_alter_table(TABLE *altered_table, + Alter_inplace_info *ha_alter_info, + bool commit) + { return false; } + + + /** + Notify the storage engine that the table structure (.FRM) has been updated. + + @note No errors are allowed during notify_table_changed(). + */ + virtual void notify_table_changed(); + +public: + /* End of On-line/in-place ALTER TABLE interface. */ + + /** use_hidden_primary_key() is called in case of an update/delete when (table_flags() and HA_PRIMARY_KEY_REQUIRED_FOR_DELETE) is defined @@ -3226,32 +3522,6 @@ protected: */ PSI_table_share *ha_table_share_psi(const TABLE_SHARE *share) const; - inline void psi_open() - { - DBUG_ASSERT(m_psi == NULL); - DBUG_ASSERT(table_share != NULL); -#ifdef HAVE_PSI_INTERFACE - if (PSI_server) - { - PSI_table_share *share_psi= ha_table_share_psi(table_share); - if (share_psi) - m_psi= PSI_server->open_table(share_psi, this); - } -#endif - } - - inline void psi_close() - { -#ifdef HAVE_PSI_INTERFACE - if (PSI_server && m_psi) - { - PSI_server->close_table(m_psi); - m_psi= NULL; /* instrumentation handle, invalid after close_table() */ - } -#endif - DBUG_ASSERT(m_psi == NULL); - } - /** Default rename_table() and delete_table() rename/delete files with a given name and extensions from bas_ext(). @@ -3301,6 +3571,14 @@ private: return HA_ERR_WRONG_COMMAND; } + /** + Update a single row. + + Note: If HA_ERR_FOUND_DUPP_KEY is returned, the handler must read + all columns of the row so MySQL can create an error message. If + the columns required for the error message are not read, the error + message will contain garbage. + */ virtual int update_row(const uchar *old_data __attribute__((unused)), uchar *new_data __attribute__((unused))) { @@ -3364,9 +3642,12 @@ private: } virtual void start_bulk_insert(ha_rows rows, uint flags) {} virtual int end_bulk_insert() { return 0; } +protected: virtual int index_read(uchar * buf, const uchar * key, uint key_len, enum ha_rkey_function find_flag) { return HA_ERR_WRONG_COMMAND; } + friend class ha_partition; +public: /** This method is similar to update_row, however the handler doesn't need to execute the updates at this point in time. The handler can be certain @@ -3451,7 +3732,16 @@ private: { return HA_ERR_WRONG_COMMAND; } virtual int rename_partitions(const char *path) { return HA_ERR_WRONG_COMMAND; } - friend class ha_partition; + virtual bool set_ha_share_ref(Handler_share **arg_ha_share) + { + DBUG_ASSERT(!ha_share); + DBUG_ASSERT(arg_ha_share); + if (ha_share || !arg_ha_share) + return true; + ha_share= arg_ha_share; + return false; + } + int get_lock_type() const { return m_lock_type; } public: /* XXX to be removed, see ha_partition::partition_ht() */ virtual handlerton *partition_ht() const @@ -3460,6 +3750,11 @@ public: inline int ha_update_tmp_row(const uchar * old_data, uchar * new_data); friend enum icp_result handler_index_cond_check(void* h_arg); +protected: + Handler_share *get_ha_share_ptr(); + void set_ha_share_ptr(Handler_share *arg_ha_share); + void lock_shared_ha_data(); + void unlock_shared_ha_data(); }; #include "multi_range_read.h" @@ -3541,6 +3836,8 @@ int ha_discover(THD* thd, const char* dbname, const char* name, int ha_find_files(THD *thd,const char *db,const char *path, const char *wild, bool dir, List<LEX_STRING>* files); int ha_table_exists_in_engine(THD* thd, const char* db, const char* name); +bool ha_check_if_supported_system_table(handlerton *hton, const char* db, + const char* table_name); /* key cache */ extern "C" int ha_init_key_cache(const char *name, KEY_CACHE *key_cache, void *); |